High Temperature Combustor and Vane Alloy

ABSTRACT

An alloy comprises, by weight: nickel (Ni) as a largest constituent; 6.0% to 7.5% chromium; up to 5.0% cobalt; 5.3% to 6.5% aluminum; up to 5.0% rhenium; 3.7% to 7.0% tungsten; and 3.7% to 7.0% tantalum.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of U.S. patent application Ser. No.16/715,463, filed Dec. 16, 2019, and entitled “High TemperatureCombustor and Vane Alloy”, which claims benefit of U.S. PatentApplication Ser. No. 62/802,909, filed Feb. 8, 2019, and entitled “HighTemperature Combustor and Vane Alloy”, the disclosure of which isincorporated by reference herein in its entirety as if set forth atlength.

BACKGROUND

The disclosure relates to nickel-based superalloys. More particularly,the disclosure relates to alloys for combustor and vane applications.

Gas turbine engine hot section components are commonly formed of alloys,typically nickel- or cobalt-based superalloys. Many components, such asblades are formed of single crystal (SX) alloys. In such single crystalcomponents, essentially the entire component is formed of a singlecontinuous crystal lattice. Typically, the orientation of that latticeis predetermined to achieve desired properties of the component. Theorientation may be assured by use of a grain starter or other castingtechniques.

When contrasted with other components such as vanes and combustorpanels, blades experience significant inertial loading. Thus, bladealloy compositions are typically specialized and differ from vane andcombustor panel alloy compositions.

Whether used on blades or on non-rotating components such as vanes andcombustor panels, the alloy substrates are typically actively cooled viaair flows (whether via internal passageways as in typical blades andvanes or via through-hole film cooling in the case of combustor panels).Such components are also often coated with thermal barrier coatings(TBC). Typical thermal barrier coatings include a bondcoat (e.g., anMCrAlY) and a barrier coat (e.g., a ceramic such as a stabilizedzirconia).

Typical failure mechanisms for such hot section components involveoxidation of the metallic substrate. Oxidation may also be accompaniedby melting, particularly at hot spots. Such failures may cause spallingof the TBC, which further increases thermal loads and impetus towardoxidation and melting.

SUMMARY

One aspect of the disclosure involves an alloy comprising, by weight:nickel (Ni) as a largest constituent; 6.0% to 7.5% chromium; up to 5.0%cobalt; 5.3% to 6.5% aluminum; up to 5.0% rhenium; 3.7% to 7.0%tungsten; and 3.7% to 7.0% tantalum.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy comprising, byweight: nickel (Ni) as said largest constituent; 6.0% to 7.0% chromium;up to 5.0% cobalt; 5.4% to 6.4% aluminum; 2.8% to 3.2% rhenium; 3.8% to6.0% tungsten; and 3.8% to 6.0% tantalum.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy comprising, byweight: nickel (Ni) as said largest constituent; 6.8% to 7.5% chromium;up to 0.5% cobalt; 5.3% to 6.5% aluminum; up to 3.25% rhenium; 3.7% to7.0% tungsten; 3.7% to 7.0% tantalum; and up to 0.30% silicon.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy comprising, byweight: nickel (Ni) as said largest constituent; 6.7% to 7.5% chromium;up to 0.5% cobalt; 5.3% to 6.5% aluminum; up to 3.25% rhenium; 3.7% to7.0% tungsten; 3.7% to 7.0% tantalum; and up to 0.30% silicon.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy comprising, byweight: nickel (Ni) as said largest constituent; 6.75% to 7.25%chromium; up to 0.5% cobalt; 5.9% to 6.4% aluminum; 2.6% to 3.2%rhenium; 3.8% to 6.2% tungsten; 3.8% to 6.2% tantalum; and up to 0.30%silicon.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy, wherein by weight:a molybdenum content, if any, is no more than 0.50%; a sulfur content,if any, is no more than 5 ppm; a hafnium content, if any is no more than0.50%; and a carbon content, if any, is no more than 0.10%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight, one or more of: amolybdenum content, if any, being no more than 0.50%; a sulfur content,if any, being no more than 5 ppm; a hafnium content, if any being nomore than 0.50%; a silicon content, if any, being no more than 0.50%;and a carbon content, if any, being no more than 0.10%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight, one or more of: amolybdenum content, if any, being no more than 0.10%; a sulfur content,if any, being no more than 1 ppm; a hafnium content being 0.050% to0.15%; a silicon content, if any, being no more than 0.30%; and a carboncontent, if any, being no more than 0.10%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: a combinedcontent, if any, of elements other than nickel, chromium, cobalt,aluminum, rhenium, tungsten, tantalum, molybdenum, if any, sulfur, ifany, hafnium, if any, silicon, if any, and carbon, if any, being no morethan 2.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: a combinedcontent, if any, of elements other than nickel, chromium, cobalt,aluminum, rhenium, tungsten, tantalum, molybdenum, if any, sulfur, ifany, hafnium, if any, silicon, if any, and carbon, if any, being no morethan 1.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: an individualcontent, if any, of every element other than nickel, chromium, cobalt,aluminum, rhenium, tungsten, tantalum, molybdenum, if any, sulfur, ifany, hafnium, if any, silicon, if any, and carbon, if any, being no morethan 1.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: an individualcontent, if any, of every element other than nickel, chromium, cobalt,aluminum, rhenium, tungsten, tantalum, molybdenum, if any, sulfur, ifany, hafnium, if any, silicon, if any, and carbon, if any, being no morethan 0.20%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of chromium, cobalt, and aluminum being 11.5% to 16.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of chromium, cobalt, and aluminum being 11.5% to 14.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of tungsten and tantalum being 8.0% to 14.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of tungsten and tantalum being 9.0% to 11.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of rhenium, tungsten, and tantalum being 9.0% to 15.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: the combinedcontent of rhenium, tungsten, and tantalum being 10.0% to 13.0%.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include, by weight: yttrium,lanthanum, and/or cerium up to 0.15% combined.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy having an incipientmelting temperature of at least 2440° F. (1338° C.)

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy having an incipientmelting temperature of at least 2460° F. (1349° C.)

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy having an incipientmelting temperature of 2460° F. to 2520° F. (1349° C. to 1382° C.) insingle-crystal (SX) form.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the alloy in single-crystal(SX) form.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include a gas turbine engine component(e.g., a combustor panel or a vane) comprising a substrate formed of thealloy.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the combustor panel furthercomprising: mounting studs.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the combustor panel furthercomprising: a thermal barrier coating atop the substrate.

A further embodiment of any of the foregoing embodiments mayadditionally and/or alternatively include the substrate being formed asa frustoconical segment.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a gas turbine engine combustor panel.

FIG. 2 is a partially schematic cross-sectional view of a coating systemon the panel of FIG. 1.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

FIG. 1 shows a turbine engine combustor panel 20 which, for purposes ofillustration is based on the combustor panel of U.S. Pat. No.,8,216,687, of Burd et al., Jul. 10, 2012, and entitled “Thermal barriercoating”. The exemplary panel 20, may be formed having a body 21 shapedas a generally frustoconical segment having inboard and outboardsurfaces 22 and 24. The exemplary panel is configured for use in anannular combustor circumscribing the engine centerline. In the exemplarypanel, the inboard surface 22 forms an interior surface (i.e., facingthe combustor interior) so that the panel is an outboard panel. For aninboard panel, the inboard surface would be the exterior surface.Accordingly, mounting features such as studs 26 extend from the outboardsurface for securing the panel relative to the engine. The exemplarypanel further includes an upstream/leading edge 28, adownstream/trailing edge 30 and lateral edges 32 and 34. Along the edgesor elsewhere, the panel may include rails or standoffs 36 extending fromthe exterior surface 24 for engaging a combustor shell (not shown). Theexemplary panel includes a circumferential array of large apertures 40for the introduction of process air. Smaller apertures (not shown) maybe provided for film cooling. Moreover, select panels may accommodateother openings for spark plug or igniter placement. Nevertheless, theteachings herein may be applied to other parts of other annularcombustors, can-type combustors, and the like, as well as vanes, fuelnozzles, and other components.

FIG. 2 shows a basic coating system 60 atop a superalloy substrate 62.The system may include a bondcoat 64 atop the substrate 62 and a TBC 66atop the bondcoat 64. In an exemplary process, the bondcoat 64 isdeposited atop the substrate surface 68. One exemplary bondcoat is aMCrAlY which may be deposited by a thermal spray process (e.g., airplasma spray) or by an electron beam physical vapor deposition (EBPVD)process. An alternative bondcoat is a diffusion aluminide deposited byvapor phase aluminizing (VPA). An exemplary characteristic (e.g., meanor median) bondcoat thicknesses 4-9 mil (100-230 micrometer). Again,other coating systems, if any, may be used. The TBC may be directly atopa surface 70 of the bondcoat 64 or of a thermally grown oxide (TGO)formed atop the bondcoat.

Several candidate alloys for improved high temperature oxidationperformance were hypothesized and were manufactured. Table I listscompositions of ten candidate alloys plus two known prior art alloys(“Prior Art 1” and “Prior Art 2”). The prior art alloys are high cobalt,high tantalum, alloys differing from each other in that one hasrelatively low sulfur content. Low sulfur content is regarded asgenerally desirable in high temperature alloys. The ten listed candidatealloys all have somewhat higher sulfur concentrations than Prior Art 2due to the limitations of laboratory-scale manufacture techniques. As isdiscussed below, commercial scale implementation may desirably havelower sulfur.

For purposes of an initial screening test, the candidate alloys of TableI were processed as equiax buttons. The buttons (and a button of thehigher sulfur Prior Art 1) were subject to cyclic furnace oxidationtesting at 2300° F. (1260° C.). Exemplary test parameters were 260cycles with a cycle time of just over 1 hour between a 2300° F. (1260°C.) hot zone (45 minute hold), a room temperature cool zone (7 minutes),and a ramp back up to 2300° F. (1260° C.) (14 minutes).

Table II shows the results of the cyclic furnace oxidation testing. Toprovide an apples-to-apples comparison, sulfur concentration needed tobe adjusted to compensate for variations in the incidental level ofsulfur amongst the test samples. Based upon known sulfur effects, theexperimentally-derived adjustment factor of Table II was applied to makeall ten candidates directly comparable to the Prior Art 2. From thistest data, it is seen that alloys D, F, G, and J are particularlypromising in all having projected life benefits in excess of five timesthat of the baseline Prior Art 2. Alloys E and H are still somewhatpromising at over four times but slightly under five times.

TABLE I Candidate and Prior Art Alloy Compositions (by weight - percentexcept where noted) Alloy Ni Cr Co Al Mo W Ta Re Hf Si S (ppm) A Bal5.16 5.17 5.59 0.01 3.79 4.01 2.57 0.09 0.01 2.9 max. max. B Bal 5.140.01 6.16 0.01 5.72 5.99 2.84 0.10 0.01 2.6 max. max. max. C Bal 5.155.12 6.17 0.01 5.62 5.98 2.75 0.09 0.01 3.2 max. max. D Bal 6.15 0.015.49 0.01 3.96 4.03 2.84 0.07 0.01 2.3 max. max. max. E Bal 6.09 5.165.47 0.01 4.08 4.01 2.92 0.08 0.01 2.0 max. max. F Bal 6.17 0.01 5.570.01 5.45 4.03 2.68 0.09 0.01 2.2 max. max. max. G Bal 6.09 5.09 6.110.01 4.08 3.94 3.24 0.09 0.01 3.9 max. max. H Bal 6.13 0.01 6.21 0.014.01 3.99 2.84 0.09 0.01 3.9 max. max. max. I Bal 7.13 5.11 6.19 0.014.06 4.01 2.83 0.09 0.01 6.1 max. max. J Bal 7.15 0.01 6.19 0.01 4.024.03 2.68 0.10 0.01 3.8 max. max. max. Prior Art 1 Bal 5.16 10.31  5.701.93 5.90 8.64 2.86 0.10 0.01 4.2 max. Prior Art 2 Bal 5.16 10.31  5.701.93 5.90 8.64 2.86 0.10 0.01 0.9 max. Alloys A-J being measuredcompositions (except for Mo and Si which are specification) Prior Art 1and 2 being nominal specification

TABLE II 2300 F. Cyclic Furnace Oxidation Test Incipient Metal MeltingLoss mils S Adjusted Life Temperature Alloy (mm) Hours/Mil (ppm)Hours/Mil Benefit** (° F. (° C.)) A 43.2 (1.10) 6.0 2.9 11.9  .78X >2500(1371) B 19.5 (0.50) 13.3 2.6 24.7 1.63X 2495 (1368) C 18.4 (0.47) 14.13.2 29.6 1.95X 2495 (1368) D 3.0 (0.076) 86.7 2.3 150 9.87X >2500 (1371)E 5.5 (0.14) 47.3 2.0 75.2 4.95X >2500 (1371) F 3.3 (0.084) 78.8 2.2125.3 8.24X >2500 (1371) G 3.6 (0.091) 72.2 3.9 170.4 11.21X  2490(1366) H 8.2 (0.21) 31.7 3.9 74.8 4.92X 2490 (1366) I 24.1 (0.61) 10.86.1 33.2 2.18X 2490 (1366) J 5.2 (0.13) 50.0 3.8 116.5 7.66X 2490 (1366)Prior Art 1 42.1 (1.07) 6.2 4.2 15.2 2440 (1338) Prior Art 2 17.1 (0.43)est 15.2 est 0.9 15.2 est   1X 2440 (1338) **Normalized relative toPrior Art 2 S content.

New specimens of those four most promising alloys plus a further Alloy Kwere processed as cast single crystal alloys. Their respectivecompositions are shown in Table III below. Alloy K was selected to befairly close to alloy D in composition but having a slightly highersilicon content. This silicon content was selected to evaluate theoxidation vs. melting temperature tradeoff. Observed reduction inincipient melting temperature (still substantially greater than theprior art incipient melting temperature) is worth the increasedoxidation life.

A 2250° F. (1232° C.) burner rig oxidation test was performed on thesealloys. Exemplary parameters are 57 minutes in burner flame and 3minutes outside the flame over a total of 933 cycles.

As seen in Table III below, particularly significant advantages werefound for alloys D, J, and K.

Differences in observed incipient melting temperature between Tables IIand III are accounted for principally by the equiax vs. single-crystal(SX) state and minor compositional variation.

Based upon these relatively significant life and temperature rangebenefits, Table IV below shows various candidate compositional ranges.Alternative ranges may be created by recombining within a group (i.e.,ranges are identified with a number identifying a group of ranges and aletter identifying a particular range in that group as in “Range 1A”)the identified ranges of elements from different particular ranges.Thus, for example, Range 1B may be modified by choosing one or moreindividual element ranges from any of Ranges 1A and 1C-1F (e.g., the 1Arange of W and the 1C range of Ta, etc.).

A further variation is to increase at least one of rhenium, tungsten,and tantalum. If the intended application is not creep limited, thebasic ranges would suffice. With higher creep capability requirementsthe rhenium, tungsten and/or tantalum could be increased. Particularexamples may be vanes where pressure differential or structural loadingrequires creep strength. Re suffers cost issues, thus, the increasedcontent may be all from W and/or Ta if cost is an issue. Total W and Tacould be up to 14.0 weight percent or up to 12.0 weight percent or up to11.0 weight percent; complementary lower limits may be 8.0 weightpercent or 9.0 weight percent. Individual contents of each couldadditionally or alternatively be up to 8.0 weight percent or 7.0 weightpercent or 6.0 weight percent. Increased Re up to 5.0 weight percent or4.0 weight percent is possible. Such upper limits on Re, Ta, and/or Wmay be substituted into Table IV below to create alternative ranges.Combined Re, W, and Ta may be in the range of 9.0 weight percent to 15.0weight percent, more narrowly 10.0 weight percent to 13.0 weightpercent. Candidates for such higher Re, W, and/or Ta alloys are shown inTable V below.

The combined oxidation and melting performance is believed related to acombined content of chromium, cobalt, and aluminum. An exemplary minimumcombined content of chromium, cobalt, and aluminum is 11.0 weightpercent or 11.5 weight percent. An exemplary maximum is 16.0 weightpercent or 14.0 weight percent. Too much could reduce meltingtemperature and introduce microstructural instability. Too little couldreduce oxidation performance.

Small amounts of elements such as yttrium, lanthanum, and/or cerium areknown in the art as improving oxidation resistance. An exemplarycombined content of Y, La, and Ce, if any is up to 0.15% or 0.10% byweight.

In various embodiments, combined content, if any, of elements other thannickel, chromium, cobalt, aluminum, rhenium, tungsten, tantalum,molybdenum, if any, sulfur, if any, hafnium, if any, silicon, if any,and carbon, if any, being no more than 2.0% or no more than 1.0% or nomore than inevitable or commercial impurity levels. Or a combinedcontent of such elements and Y, La, and Ce, if any may be no more thaninevitable or commercial impurity levels.

TABLE III 2250° F. Burner Rig Oxidation Test Test Incipient Time toMelting Component (by weight - percent except where noted) 1% Wt LifeTemperature Alloy Ni Cr Co Al Mo W Ta Re Hf Si S ppm Loss Benefit (° F.(° C.)) D Bal 6.21 0.04 5.42 0.01 4.04 4.04 3.00 0.13 0.02 0.93 8141.61X 2515 (1379) F Bal 6.22 0.02 5.61 0.01 5.41 4.05 3.02 0.11 0.030.43 539 1.07X 2505 (1374) G Bal 6.22 4.90 6.33 0.01 3.95 4.03 3.04 0.100.03 2.10 594 1.18X 2495 (1368) J Bal 6.91 0.01 6.18 0.01 3.99 4.02 3.000.11 0.03 0.91 879 1.74X 2475 (1357) K Bal 6.23 0.01 5.45 0.01 3.89 3.982.97 0.12 0.24 0.98 1534 3.04X 2495 (1368) Prior Art 2 Bal 4.98 10.025.63 1.88 5.87 8.71 3.00 0.09 0.03 0.30 505   1X 2440 (1338) All(including Prior Art 2) being measured compositions.

TABLE IV Candidate Compositional Ranges (by weight - percent exceptwhere noted) Alloy Ni Cr Co Al Re Mo W Ta Hf Si C S Range 1A Bal 6.0-7.5to 5.0 5.3-6.5 to 5.0  to 0.50 3.7-7.0 3.7-7.0 0.050-0.50 to 0.30 to0.10 to 5 ppm Range 1B Bal 6.0-7.0 to 5.0 5.4-6.4 2.8-3.2 to 0.103.8-6.0 3.8-6.0 0.050-0.15 to 0.30  to 0.050 to 1 ppm Range 1C Bal6.0-7.5 to 5.0 5.3-6.5 to 5.0  to 0.50 3.7-5.6 3.7-4.4 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 1D Bal 6.0-7.0 to 5.0 5.4-6.4 2.8-3.2 to0.10 3.8-5.5 3.8-4.2 0.050-0.15 to 0.30  to 0.050 to 1 ppm Range 1E Bal6.0-7.5 to 5.0 5.3-6.5 2.5-3.3 to 0.50 3.7-5.6 4.2-5.2 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 1F Bal 6.0-7.0 to 5.0 5.4-6.4 2.8-3.2 to0.10 3.8-5.5 4.4-5.1 0.050-0.15 to 0.30  to 0.050 to 1 ppm Range 1G Bal6.0-7.2 to 5.0 5.3-6.4 to 5.0  to 0.50 3.7-7.0 3.7-7.0 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 2A Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25 to0.50 3.7-7.0 3.7-7.0 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 2B Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-6.0 3.8-6.0 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 2C Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-5.6 3.7-4.4 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 2D Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-5.5 3.8-4.2 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 2E Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-5.6 4.2-5.2 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 2F Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-5.5 4.4-5.1 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 3A Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-4.4 3.7-7.0 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 3B Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-4.2 3.8-6.0 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 3C Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-4.4 3.7-4.4 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 3D Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-4.2 3.8-4.2 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 3E Bal 6.0-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-4.4 4.2-5.2 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 3F Bal6.0-7.0 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-4.2 4.4-5.1 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 4A Bal 6.8-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-7.0 3.7-7.0 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 4B Bal7.0-7.5 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-6.0 3.8-6.0 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 4C Bal 6.8-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-5.6 3.7-4.4 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 4D Bal7.0-7.5 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-5.5 3.8-4.2 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 4E Bal 6.8-7.5 to 0.5 5.3-6.5 to 3.25to 0.50 3.7-5.6 4.2-5.2 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 4F Bal7.0-7.5 to 0.1 5.4-6.4 2.8-3.2 to 0.10 3.8-5.5 4.4-5.1 0.050-0.15 0.15to 0.25  to 0.050 to 1 ppm Range 4G Bal 6.8-7.2 to 0.5 6.0-6.4  2.9-3.25to 0.50 3.7-4.2 3.7-4.2 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 4H Bal6.7-7.5 to 0.5 5.3-6,5 to 3.25 to 0.50 3.7-7.0 3.7-7.0 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 4I Bal 7.0-7.5 to 0.1 5.4-6.4 2.7-3.2 to0.10 3.8-6.2 3.8-6.2 0.050-0.15 0.15 to 0.30  to 0.050 to 1 ppm Range 4JBal 6.7-7.5 to 0.5 5.3-6.5 to 3.25 to 0.50 3.7-5.6 3.7-4.4 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 4K Bal 7.0-7.5 to 0.1 5.4-6.4 2.7-3.2 to0.10 3.8-5.5 3.8-4.2 0.050-0.15 0.15 to 0.30  to 0.050 to 1 ppm Range 4LBal 6.7-7.5 to 0.5 5.3-6.5 to 3.25 to 0.50 3.7-5.6 4.2-5.2 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 4M Bal 7.0-7.5 to 0.1 5.4-6.4 2.7-3.2 to0.10 3.8-5.5 4.4-5.1 0.050-0.15 0.15 to 0.30  to 0.050 to 1 ppm Range 4NBal 6.7-7.2 to 0.5 6.0-6.4  2.9-3.25 to 0.50 3.7-4.2 3.7-4.2 0.050-0.50to 0.30 to 0.10 to 5 ppm Range 5A Bal 6.0-6.5 to 5.0 5.3-6.5 to 3.25 to0.50 3.7-7.0 3.7-7.0 0.050-0.50 to 0.30 to 0.10 to 5 ppm Range 5B Bal6.0-6.5 to 0.5 5.3-6.5 to 3.25 to 0.50 3.7-7.0 3.7-7.0 0.050-0.50 to0.30 to 0.10 to 5 ppm Range 5C Bal 6.0-6.5 to 0.5 5.3-6.4  2.9-3.25 to0.50 3.7-5.5 3.7-4.2 0.050-0.50 to 0.30 to 0.10 to 5 ppm The balancenickel is exclusive of minor additions and impurities at levelsdiscussed below.

TABLE V Higher Re, W, and/or Ta Candidate Alloy Compositions (byweight - percent except where noted) Alloy Ni Cr Co Al Mo W Ta Re Hf SiS (ppm) L Bal 7.25 0.1 max. 6.25 0.1 max. 5.0 5.0 3.0 0.1 0.2 1.0 max. MBal 7.25 0.1 max. 6.25 0.1 max. 6.0 6.0 3.0 0.1 0.0 1.0 max. N Bal 7.250.1 max. 6.25 0.1 max. 4.0 4.0 4.0 0.1 0.2 1.0 max. O Bal 7.25 0.1 max.6.25 0.1 max. 2.0 4.0 5.0 0.1 0.2 1.0 max. P Bal 7.25 0.1 max. 6.25 0.1max. 3.0 4.0 4.0 0.1 0.2 1.0 max. Q Bal 7.25 0.1 max. 6.25 0.1 max. 1.05.0 5.0 0.1 0.2 1.0 max. R Bal 7.00 0.1 max. 6.00 0.1 max. 5.0 5.0 3.00.1 0.2 1.0 max. S Bal 7.00 0.1 max. 6.00 0.1 max. 6.0 6.0 3.0 0.1 0.01.0 max. T Bal 7.25 0.1 max. 6.25 0.1 max. 4.0 6.0 3.0 0.1 0.2 1.0 max.U Bal 7.25 0.1 max. 6.25 0.1 max. 2.0 7.0 5.0 0.1 0.2 1.0 max.

To validate the Table V alloys, further alloy examples were made andtested. Table VI through Table IX show data regarding these alloys andtests. Table VI shows measured compositions of three such alloys alongwith nominal compositions for four prior art alloys including two of theprior art alloys discussed above. The Prior Art 1 and Prior Art 2 alloyswere from different batches/heats than those previously tested. Thus,nominal values are given. In the Prior Art 1 and Prior Art 3 alloys,sulfur concentration is not controlled/limited (unlike the limits ofPrior Art 2 and Prior Art 4). Experience indicates that sulfurconcentration in such commercial alloys is typically four PPM orsomewhat greater.

Table VII has test data for three specimens of Alloy V, three specimensof Alloy W, and two specimens each of Alloy J, Prior Art 2, and PriorArt 4. The Alloy J was from the same batch/heat/composition of TableIII. For each alloy, the test results are given with average valueimmediately below. Prior Art 2 is used to normalize and provide relativelife columns. At both 2250 F and 2150 F, time to 0.5% weight loss wasmeasured along with time to 1% weight loss at 2150 F. For bothtemperatures, a metallography maximum attack was measured as theper-side combination of material loss and depth of an aluminum-depletedregion therebelow. This max. attack parameter was then converted into anhours per mil life parameter. Significant life improvements are shownrelative to both prior art alloys.

Such life improvements are particularly significant relative to creepand tensile strength properties (discussed below) in combustor panel,vane, and other static structures contrasted with blades. Centrifugalloading on blade airfoils and attachment roots puts a premium on creepand tensile strength properties. Combustor components (e.g., floatwallpanels formed as frustoconical segments, bulkheads, nozzles, combustorcans) are generally under essentially no centrifugal loading and littleor no external loading. Similarly, vanes will be under no centrifugalloading and little external loading (e.g., typically carrying a smallload across an airfoil from a seal at an inner platform to an outershroud, but sometimes functioning as structural struts or the like).

Table VIII provides creep rupture data for three specimens each ofAlloys V and W and their averages along with values for Prior Art 1 andPrior Art 3. The prior art alloy data was based upon published datarather than simultaneous testing along with the other two alloys. Inthis case, Alloy W actually shows improved creep capability over PriorArt 3 but a debit relative to Prior Art 1. Alloy V shows a creep debitrelative to both prior art alloys. Alloy W had improved creep capabilityover Alloy V due to a higher refractory content and gamma prime volumefraction. Such debits are immaterial for nonrotating componentapplications.

Table IX contains tensile property data for three specimens each ofAlloy V and Alloy W at each of four temperatures along with averages foreach group of specimens at each temperature. Alloy V shows a tensiledebit relative to Prior Art 1 and 3. Alloy W actually shows improvedtensile capability over Prior Art 3 but a debit relative to Prior Art 1.No prior art data is provided because the prior art alloys' tensilecapability correlates well with the creep rupture capability. From thisit is seen that both Alloys V and W display a yield strength increase asa function of temperature typical of nickel-base superalloys. At testtemperatures closer to the gamma prime solvus, the tensile capability ofboth alloys is reduced significantly due to a lower gamma prime volumefraction. In any event, such tensile debits are immaterial fornonrotating component applications.

TABLE VI Further Higher Re, W, and/or Ta Candidate and Prior Art AlloyCompositions (by weight - percent except where noted) Alloy Ni Cr Co AlMo W Ta Re Ti Hf B Zr C Si S J Bal 6.91 ** 6.18 ** 3.99 4.02 3.0 ** 0.11** ** 0.031 0.03 0.91 ppm V Bal 7.07 ** 6.13 ** 4.88 5.05 2.9 ** 0.11 **** 0.014 0.23 0.52 ppm W Bal 7.13 ** 6.17 ** 5.7 6 2.92 ** 0.11 ** **0.012 0.04 0.65 ppm Prior Art 1 * Bal 5.0 10.0 5.65 1.9 5.9 8.7 3.0 **0.1 ** ** ** ** *** Prior Art 2 * Bal 5.0 10.0 5.65 1.9 5.9 8.7 3.0 **0.1 ** ** ** ** 1 ppm max Prior Art 3 * Bal 10.0 5.0 5.0 ** 4.0 12.0 0.01.5 ** ** ** ** ** *** Prior Art 4 * Bal 8.0 10.0 6.0 6.0 ** 4.25 0.01.0 1.15 0.015 0.08 0.11  ** 1 ppm max * nominal - others measured **maximum aggregate minor alloying element concentration of 0.3 wt % foreach alloy *** not controlled, typically 4 ppm or somewhat greater.

TABLE VII Uncoated Burner Rig Oxidation Testing 2250 F. 2150 F. TimeTime Time to to Rel to 0.5% Rel. Max Hr/ 0.5% Life 1% Rel. Max. Hr/Weight Wt. Life At- Mil Weight Wt Based Wt Life At- Mil Time Loss, Loss0.5% tack Hr/ Rel. Time Loss, Loss on 0.5% Loss, 1% tack Hr/ Rel Alloy(hours) (grams) (hours) Loss (mils) Mil Life (hours) (grams) (hours)Loss (hours) Loss (mils) Mil Life V 850.5 0.67 623 20.9 40.7 1685.50.549 1427 ~2792  6.6 255.4 850.5 0.74 549 8.1 105.0 1685.5 0.56  1371~2523 17.5 96.3 850.5 0.77 551 7.8 109.0 1685.5 0.584 1256 ~3045 14.6115.4 Avg. 574 6.84X 84.9 4.49X Avg. 1351 6.33X ~2789 7.95X Avg. 155.73.65X W 850.5 1.79 443 23.2 36.7 1685.5 1.009 1005 1619 28.6 58.9 850.52.23 428 30.4 28.0 1685.5 0.948 1019 1654 20.6 81.8 850.5 2.42 402 29.728.6 1685.5 1.135 915 1541 21.6 78.0 Avg. 424 5.05X 31.1 1.65X Avg. 9804.59X 1605 4.57X AVE 72.9 1.71X J 670.5 1.16 322 94.7 7.1 1484.5 1.053803 1430 27.6 53.8 670.5 1.05 330 17.0 39.4 1484.5 0.907 875 1505 24.161.6 Avg. 326 3.88X 23.3 1.23X Avg. 839 8.61X 1468 4.18X Avg. 57.7 1.35XPrior 631 10.4  74 41.9 15.1 1284.5 7.687 214 330 33.3 38.6 Art 2 6317.96 94 27.9 22.6 1284.5 6.352 213 371 27.5 46.7 1284.5 Avg. 84   1X18.9   1X Avg. 213.5   1X 351   1X Avg. 42.7   1X Prior 501 5.73 95 37.813.3 420.0 9.175 70 120 0.34X 59.5 7.1 Art 4 381 7.55 44 97.5 3.9 883.56.497 193 308 0.88X 48.6 18.2 Avg. 70  .83X 8.6  .46X Avg. 131.5 0.62X224  .61X Avg. 12.7 0.30X

TABLE VIII Creep-Rupture Properties 1400 F./110 ksi 1800 F./36 ksi 2000F./15 ksi Rupture Time to Rupture Time to Rupture Time to Life 1% CreepLife 1% Creep Life 1% Creep Alloy (hours) (hours) (hours) (hours)(hours) (hours) W 124*  13.2 41.4* 31.3 125*  57.5  79* 7.0 55.7* 13.1126*  64.8 221*  17.1 46.5* 10.3 117*  88.7 Avg. W 141   12.4 49.8 17128.3 83.5 X 626.6 42.6 117.3 42.7 547.8 441.0 591.3 23.5 116.2 39.3623.7 525.0 587.1 27.6 107.8 37.9 641.7 594.0 Avg. X 601.7 31.2 113.8 40604.4 520.0 Prior 256   7 90 35 110   50 Art 3 Prior 200   4 300 1301400   800 Art 1 *Note: Specimens failed prematurely at the extensometerattachment points. A modified test specimen design corrected this issuefor other tests.

TABLE IX Tensile Properties Area Temperature Yield Stress Ult. StressModulus Red. El. Alloy (° F.) (ksi) (ksi) (Msi) (%) (%) W  70 118.9144.7 19.0 23.0 21.0 116.8 143.8 18.8 30.0 34.0 124.4 157.7 19.0 18.018.0 Avg. 120.0 148.7 18.9 23.7 24.3 1200 116.1 134.9 16.2 32.0 21.0119.3 142.2 15.8 26.0 17.0 123.9 149.1 15.6 18.0 14.0 Avg. 119.8 142.015.9 25.3 17.3 1400 132.5 155.3 14.9 30.0 11.0 135.2 157.9 15.0 21.010.0 122.4 142.5 15.3 33.0 11.0 Avg. 130.0 151.9 15.1 28.0 10.7 210022.5 37.8 8.0 82.0 34.0 22.0 36.9 7.7 83.0 31.0 22.5 38.0 7.7 78.0 31.0Avg. 22.3 37.6 7.8 81.0 32.0 X  70 128.4 162.0 18.6 16.0 14.0 118.5140.9 19.3 23.0 26.0 126.2 154.8 18.9 18.0 14.0 Avg. 124.4 152.6 18.919.0 18.0 1200 132.1 155.2 15.7 17.0 12.0 128.5 155.65 15.64 28.0 12.0134.5 160.5 15.7 17.0 13.0 Avg. 131.7 157.1 15.7 20.7 12.3 1400 137.1161.5 15.6 29.0 10.0 146.9 166.7 15.0 22.0 7.5 136.1 156.82 15.39 27.07.5 Avg. 140.0 161.67 15.31 26.0 8.3 2100 28.5 46.8 8.8 76.0 28.0 28.646.0 8.4 77.0 34.0 29.7 48.2 8.5 74.0 31.0 Avg. 29.0 47.0 8.6 75.7 31.0

The use of “first”, “second”, and the like in the following claims isfor differentiation within the claim only and does not necessarilyindicate relative or absolute importance or temporal order. Similarly,the identification in a claim of one element as “first” (or the like)does not preclude such “first” element from identifying an element thatis referred to as “second” (or the like) in another claim or in thedescription.

Where a measure is given in English units followed by a parentheticalcontaining SI or other units, the parenthetical's units are a conversionand should not imply a degree of precision not found in the Englishunits.

One or more embodiments have been described. Nevertheless, it will beunderstood that various modifications may be made. For example, whenapplied to an existing baseline configuration, details of such baselinemay influence details of particular implementations. Accordingly, otherembodiments are within the scope of the following claims.

What is claimed is:
 1. An alloy comprising, by weight: nickel (Ni) as alargest constituent; 6.0% to 7.5% chromium; up to 5.0% cobalt; 5.3% to6.5% aluminum; up to 5.0% rhenium; 3.7% to 7.0% tungsten; and 3.7% to7.0% tantalum.
 2. The alloy of claim 1 comprising, by weight: nickel(Ni) as said largest constituent; 6.0% to 7.0% chromium; up to 5.0%cobalt; 5.4% to 6.4% aluminum; 2.8% to 3.2% rhenium; 3.8% to 6.0%tungsten; and 3.8% to 6.0% tantalum.
 3. The alloy of claim 1 comprising,by weight: nickel (Ni) as said largest constituent; 6.8% to 7.5%chromium; up to 0.5% cobalt; 5.3% to 6.5% aluminum; up to 3.25% rhenium;3.7% to 7.0% tungsten; 3.7% to 7.0% tantalum; and up to 0.30% silicon.4. The alloy of claim 1 comprising, by weight: nickel (Ni) as saidlargest constituent; 6.7% to 7.5% chromium; up to 0.5% cobalt; 5.3% to6.5% aluminum; up to 3.25% rhenium; 3.7% to 7.0% tungsten; 3.7% to 7.0%tantalum; and up to 0.30% silicon.
 5. The alloy of claim 1 comprising,by weight: nickel (Ni) as said largest constituent; 6.75% to 7.25%chromium; up to 0.5% cobalt; 5.9% to 6.4% aluminum; 2.6% to 3.2%rhenium; 3.8% to 6.2% tungsten; 3.8% to 6.2% tantalum; and up to 0.30%silicon.
 6. The alloy of claim 5 wherein, by weight: a molybdenumcontent, if any, is no more than 0.50%; a sulfur content, if any, is nomore than 5 ppm; a hafnium content, if any is no more than 0.50%; and acarbon content, if any, is no more than 0.10%.
 7. The alloy of claim 1wherein, by weight, one or more of: a molybdenum content, if any, is nomore than 0.50%; a sulfur content, if any, is no more than 5 ppm; ahafnium content, if any is no more than 0.50%; a silicon content, ifany, is no more than 0.50%; and a carbon content, if any, is no morethan 0.10%.
 8. The alloy of claim 1 wherein, by weight, one or more of:a molybdenum content, if any, is no more than 0.10%; a sulfur content,if any, is no more than 1 ppm; a hafnium content is 0.050% to 0.15%; asilicon content, if any, is no more than 0.30%; and a carbon content, ifany, is no more than 0.10%.
 9. The alloy of claim 1 wherein, by weight:a combined content, if any, of elements other than nickel, chromium,cobalt, aluminum, rhenium, tungsten, tantalum, molybdenum, if any,sulfur, if any, hafnium, if any, silicon, if any, and carbon, if any, isno more than 2.0%.
 10. The alloy of claim 1 wherein, by weight: acombined content, if any, of elements other than nickel, chromium,cobalt, aluminum, rhenium, tungsten, tantalum, molybdenum, if any,sulfur, if any, hafnium, if any, silicon, if any, and carbon, if any, isno more than 1.0%.
 11. The alloy of claim 1 wherein, by weight: anindividual content, if any, of every element other than nickel,chromium, cobalt, aluminum, rhenium, tungsten, tantalum, molybdenum, ifany, sulfur, if any, hafnium, if any, silicon, if any, and carbon, ifany, is no more than 1.0%.
 12. The alloy of claim 1 wherein, by weight:an individual content, if any, of every element other than nickel,chromium, cobalt, aluminum, rhenium, tungsten, tantalum, molybdenum, ifany, sulfur, if any, hafnium, if any, silicon, if any, and carbon, ifany, is no more than 0.20%.
 13. The alloy of claim 1 wherein, by weight:the combined content of chromium, cobalt, and aluminum is 11.5% to16.0%.
 14. The alloy of claim 1 wherein, by weight: the combined contentof chromium, cobalt, and aluminum is
 11. 5% to 14.0%.
 15. The alloy ofclaim 14 wherein, by weight: the combined content of tungsten andtantalum is 8.0% to 14.0%.
 16. The alloy of claim 14 wherein, by weight:the combined content of tungsten and tantalum is 9.0% to
 11. 0%.
 17. Thealloy of claim 1 wherein, by weight: the combined content of rhenium,tungsten, and tantalum is 9.0% to 15.0%.
 18. The alloy of claim 17wherein, by weight: the combined content of rhenium, tungsten, andtantalum is 10.0% to 13.0%.
 19. The alloy of claim 1 further comprising,by weight: yttrium, lanthanum, and/or cerium up to 0.15% combined. 20.The alloy of claim 1 having an incipient melting temperature of at least2440° F. (1338° C.)
 21. The alloy of claim 1 having an incipient meltingtemperature of at least 2460° F. (1349° C.)
 22. The alloy of claim 1having an incipient melting temperature of 2460° F. to 2520° F. (1349°C. to 1382° C.) in single-crystal (SX) form.
 23. The alloy of claim 1 insingle-crystal (SX) form.
 24. A gas turbine engine component comprisinga substrate formed of the alloy of claim 1.